In many medical situations, when an instrument is to be inserted into a patient's throat through his mouth, there is a need to protect both the inserted instrument and the teeth of the patient against damage by biting action. There is also a need to secure the inserted instrument so as to prevent it from excessive movement in the mouth-cavity which could both adversely affect the function of the instrument and cause damage to the patient. These needs are of special significance when the patient cannot control his movements, for example under narcosis, and when a reliable functioning of the inserted instrument is essential. Thus, it has been a general rule that some kind of teeth-shield of semi-rigid material should be placed between the patient's teeth during operations when a tube (e.g. an endotracheal tube) is inserted down the trachea of the patient and through which the patient is provided with oxygen or anaesthetic gas.
Heretofore rolls of textile fabric or pieces of tubing of suitable dimensions have been used as teeth-shields. The main problem with these types of teeth-shields has been the difficulty in rigidly fixing the instrument adjacent to the teeth-shield and also in fixing this unit rigidly in the mouth of the patient so that the unit is prevented from performing rotational movements or movement either out of the mouth-cavity or deeper down into the throat. This fixing must be achieved to make it possible for the teeth-shield to perform its purposes of offering resistance to biting before the instrument comes into contact with the teeth and to guarantee a proper positioning of the instrument for correct functioning in the patient. In an effort to achieve fixation of the shield and the instrument sticking-plaster or special tapes have been used. In this way enough friction has usually been obtained to hold together an instrument and a teeth-shield. However, the sticking-plaster or tape has had the disadvantage that it becomes soaked with saliva or blood and often adheres to the patient's hair or beard or even to the skin. A teeth-shield in the shape of a roll has had the added disadvantage of providing very little space for insertion of additional instruments through the mouth.
German Offenlegungsschrift No. 2,120,164 proposes arranging a body of soft material around a tube to be inserted into the mouth and to give this body such a size as to prevent it from penetrating too deeply into the mouth. This device is, however, not generally usable since the opening through the body must be varied in size in accordance with the size of each tube or group of tubes that are to be used in order to prevent free movement. As a consequence of its size and because the tubing completely fills up the opening, this device doesn't provide any space for the insertion of additional instruments and also cannot be maintained at a fixed location in the mouth-cavity.
The object with the present invention is to provide a device for insertion of instruments, such as tubes, probes, etc., through the mouth of a patient by aid of which the above discussed problems are reduced or eliminated.